Benzoic acid derivatives for the treatment of diabetes mellitus

ABSTRACT

The present invention relates to the use of certain benzoic acid derivatives of formula (I), as disclosed in the specification, which act as peroxisome proliferator activated receptor (PPAR) agonists, in particular states of insulin resistance including type 2 gamma receptors (PPAR), and so are useful therapeutically in the treatment of diabetes mellitus. Novel pharmaceutical compositions and novel compounds are also defined, together with methods of their production.

The present invention relates to the use of certain benzoic acidderivatives which act as peroxisome proliferator activated receptor(PPAR) agonists, in particular gamma receptors (PPARγ), and so areuseful in the treatment of states of insulin resistance, including type2 diabetes mellitus. Novel pharmaceutical compositions and novelcompounds are also defined, together with methods of their production.

Traditionally, therapeutic intervention in type 2 diabetes has had a‘glucocentric focus’ dominated by the use of insulin secretogogues e.g.the sulphonylureas and the measurement of glycated haemoglobin (HbA1c)or fasting blood sugar level (FPG) as indices of diabetic control. Inthe USA, patients with type 2 diabetes are usually treated with dietand, when needed, a sulphonylurea compound. However, it is estimatedthat approximately 30% of patients initially treated with sulphonylureaagents have a poor response and in the remaining 70%, the subsequentfailure rate is approximately 45% per annum. Other estimates put failurerates higher with few patients responding after 10 years therapy. Atreatment-related increase in body weight is also experienced with theseagents. Prior to the FDA approval of metformin in 1995, the onlytherapeutic option for type 2 diabetic patients, in whom sulphonylureatherapy had failed, was insulin.

Despite the introduction of newer agents both the incidence andprevalence of type 2 diabetes continues to increase on a global basis.Approximately 16 million people in the USA have diabetes mellitus,90-95% of whom have type 2 disease. This represents an enormoushealthcare burden; estimated in 1998 to be some $98 billion per annum indirect and indirect healthcare costs. Recently, both the ADA and WHOhave revised guidelines for the diagnosis of diabetes and classifieddiabetes more according to aetiology. The threshold for diagnosis(FPG>126 mg/dl) has been lowered and the term ‘type 2’ is now used todescribe mature onset diabetics who have not progressed to insulintherapy. After the ADA implemented these new criteria in 1997, theprevalence of the type 2 disease sector increased by nearly 6 millionpeople in the seven major pharmaceutical markets (France, Germany,Italy, Japan, Spain, UK and USA).

Apart from often mild acute symptoms, type 2 diabetics are also at aconsiderable risk of developing long term complications of the disease.These include a 4-5 fold higher risk, (compared with non-diabetics), ofdeveloping macrovasular disease including CHD and PVD and microvascularcomplications including retinopathy, nephropathy and neuropathy. In manyindividuals, overt type 2 diabetes is preceded by a period of reducedinsulin sensitivity (insulin resistance), accompanied by a cluster ofother cardiovascular risk factors, collectively termed as insulinresistance syndrome (IRS).

It has been estimated that approximately 80% of type 2 diabetics areobese and other co-morbidities of the IRS include: dyslipidemia,hyperinsulineria, raised arterial blood pressure, uricemia and a reducedfibrinolysis. Given the increased global prevalence and incidence oftype 2 diabetes and the very high costs of treating the long termcomplications of the disease there is tremendous interest in thedevelopment of agents that delay or prevent the onset of type 2 diabetesand in those that reduce the risk of cardiovascular complicationsassociated with IRS. These activities have lead to the introduction ofthe thiazolidinedione (TZD) class of insulin sensitisers that improvedthe dyslipidemia and thus restored the insulin sensitivity leading toimproved glycemic control and lower HbA1c levels.

Although the complex interplay between lipids and carbohydrates asmetabolic fuels has been recognised for many decades it is onlyrecently, that researchers and clinicians have begun to focus on theimportance of dyslipidemia seen in type 2 diabetes. Much has been madeof the relative sensitivities of muscle, liver and adipose tissues toinsulin and a case for the primacy of insulin resistance in adiposetissue leading to the IRS has been debated. A typical dyslipidemicatherogenic lipoprotein phenotype (referred to as type B) is seen in IRSincluding frequently in type 2 diabetics, characterised by a modestlyraised LDL-C, a more significant increase in VLDL-TG and reduced HDL.Apparently, changes in the physicochemical properties of VLDL-TGparticles result in slower plasma clearance rates and in the generationof small dense LDL particles. The latter permeate the vascularendothelium more readily and are more prone to oxidation and glyrationand are considered to play a critical role in atherogenesis in largevessels. Although more difficult to measure, improved free fatty acid(IFFA) flux is increasingly considered to play an important role in theIRS affecting metabolic events in muscle, liver, adipose tissue andpancreas.

The first generation TZDs e.g. troglitazone, pioglitazone, rosiglitazonewere in clinical development before the putative mechanism of action wasdiscovered and published in 1995 (PPARγ activation). It is clear fromexperience with these first generation agents that it is difficult topredict from animal pharmacology the safety and efficacy profile theseagents will have in the clinic. Thus, knowledge of the putativemechanism of action of this class coupled with concerns regardingsafety, offers the opportunity to identify non-TZD activators of PPARfor the treatment of type 2 diabetes and is the subject of thisinvention. Furthermore, we recognise that agents with a dual action atboth α and g PPAR may have additional benefits in reducing diabeticco-morbidities, particularly raised triglycerides. Such agents may beuseful in the treatment of type 2 diabetes, the IRS, dyslipidemia and inreducing risk of cardiovascular disease.

Certain heterocyclic amides and their use as leukotriene antagonists isdescribed in EP-A-179619. Additional phenyltetrazole leukotriene D₄receptor antagonists have been described by Sawyer et al., J. Med. Chem.1992, 35, 7, 1200-1209.

The present invention provides the use of a compound of formula (I)

or a pharmaceutically acceptable salt or ester thereof, in thepreparation of a medicament for use in the activation of PPAR,

where Q, X, Y and Z are either —CR^(a)═, —CR^(b)═CR^(c)— or —N═; whereR^(a), R^(b) and R^(c) are independently selected from hydrogen, halo ora bond, such that together with the nitrogen atom to which Y and Z areattached, they form a five or six-membered aromatic ring;

R¹ and R³ are independently selected from C₁₋₃alkyl, halo,haloC₁₋₃alkyl, C₁₋₃alkoxy, or haloC₁₋₃alkoxy;

n and m are independently selected from 0, 1 or 2;

A is an alkylene, alkenylene or alkynylene chain optionally interposedby a heteroatom; and

R² is an optionally substituted aryl, optionally substitutedheterocyclyl or optionally substituted cycloalkyl moiety.

As used herein, the term “hydrocarbyl” refers to alkyl, alkenyl,alkynyl, aryl, aralkyl, cycloalkyl, cycloalkenyl or cycloalkynyl groups.

As used herein the term “heterocyclyl” refers to single or fused ringstructures which, unless stated otherwise, may be aromatic ornon-aromatic in nature and which suitably contain from 2 to 20 ringatoms, suitably from 5 to 8 ring atoms, at least one of which andsuitably up to four of which are heteroatoms. The term “heteroatom”includes oxygen, sulphur and nitrogen. Where a heteroatom is nitrogen,it will be further substituted for example by hydrogen or an alkylgroup.

In this specification the term “aryl” refers to phenyl, biphenyl andnaphthyl.

The term “heterocyclyl” includes aromatic or non-aromatic rings, forexample containing from 4 to 20, Examples of such groups include furyl,thienyl, pyrrolyl, pyrrolidinyl, imidazolyl, triazolyl, thiazolyl,tetrazolyl, oxazolyl isoxazolyl, pyrazolyl, pyridyl, pyrimidinyl,pyrazinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl,quinoxalinyl, benzothiazolyl, benzoxazolyl, benzothienyl or benzofuryl.

“Heteroaryl” refers to those groups described above which have anaromatic character.

In this specification the term “alkyl” when used either alone or as asuffix includes straight chain or branched structures. These groups maycontain up to 10, preferably up to 6 and more preferably up to 4 carbonatoms. Similarly the terms “alkenyl” and “alkynyl” refer to unsaturatedstraight or branched structures containing for example from 2 to 10,preferably from 2 to 6 carbon atoms. Cyclic moieties such as cycloalkyl,cycloalkenyl and cycloalkynyl are similar in nature but have at least 3carbon atoms, suitably from 3 to 20 carbon atoms and preferably from 3to 7 carbon atoms. Terms such as “alkoxy” comprise alkyl groups as isunderstood in the art.

The term “halo” includes fluoro, chloro, bromo and iodo. References toaryl groups include aromatic carbocylic groups such as phenyl andnaphthyl.

Preferably, the group comprising —Y—X—Q—Z— and the nitrogen to which itis attached forms a 5-membered aromatic ring. Preferably however, anyother heteroatoms in this ring are also nitrogen. Examples of suchgroups include tetrazolyl, triazolyl, pyrazolyl, imidazolyl pyrrolyl,pyridyl, pyridazinyl or pyrimidinyl, and preferably tetrazolyl,pyrazolyl or imidazolyl.

Thus examples of the group formed by —Y—X—Q—Z and the nitrogen atom towhich they are attached include the following groups (i) to (vii);

where R^(d) and R^(c) are independently selected from hydrogen or halo,preferably hydrogen, * indicates the nitrogen atom illustrated informula (I) and + indicates the point of attachment to he group —A—R².

Suitable optional substituents for the group R² include alkyl, alkenyl,alkynyl, aryl, heterocyclyl, alkoxy, aralkyl, cycloalkyl, cycloalkenylcycloalkynyl, halo, cyano, nitro, C(O)_(a)R⁸, OR⁸, S(O)_(b)R⁸, NR⁹R¹⁰,C(O)NR⁹R¹⁰, OC(O)NR⁹R¹⁰, NR⁸C(O)_(a)R⁹, NR⁸CONR⁹R¹⁰, N═CR⁹R¹⁰,S(O)_(b)NR⁹R¹⁰ or NR⁸S(O)_(b)R¹⁰ where R⁸, R⁹ and R¹⁰ are independentlyselected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heterocyclyl,alkoxy, aralkyl, cycloalkyl, cycloalkenyl or cycloalkynyl, any of whichmay themselves be optionally substituted, a is 1 or 2 and b is 0, 1, 2or 3.

Suitable optional substituents for alkyl, alkenyl, alkynyl, aryl,heterocyclyl, alkoxy, aralkyl, cycloalkyl, cycloalkenyl or cycloalkynylgroups R⁸, R⁹ and R¹⁰ include halo, nitro cyano, alkanoyl such asacetyl, oxo, carboxy or salts or esters thereof; alkoxy such as methoxy,ethoxy or propoxy, aryloxy such as phenoxy, thioalkyl such asthiomethyl, thioethyl or thiopropyl, sulphate, haloalkyl such astifluoromethyl, aryl such as phenyl, carbamate, amino, mono- or di-alkylamino such as methylamino or di-methylamino. Aryl, heterocyclyl oraralkyl groups R⁸, R⁹ and R¹⁰ may further be substituted by alkyl,alkenyl or alkynyl groups suitably having from 1 to 4 carbon atoms.

In particular R² is an optionally substituted heterocyclic group, suchas pyridyl, indole, quinoline, isoquinoline, benzimidazoline,benzpyrazole.

Preferred optional substituents for such groups include alkyl, aryl andgroups of formula NR⁸C(O)_(a)R⁹ where R⁸, R⁹ and a are as defined above.

Where R² is substituted by a group NR⁸C(O)_(n)R⁹, R⁸ is preferablyhydrogen, whilst R⁹ is preferably alkyl, such as C₁₋₆ alkyl, orcycloalkyl, such as cyclopentyl.

Suitably R³ is alkoxy in particular methoxy or halo such as bromo.Preferably m is 0 or 1.

Suitable groups for A include —(CH₂)_(p)—, —O(CH₂)_(p)—, —(CH₂)_(p)O——(CH₂)_(p)—, —NR⁵(CH₂)_(p)— or —(CH₂)_(p)NR⁵— where p is an integer of 1to 3 and is preferably 1 and R⁵ is hydrogen or alkyl, in particular C₁₋₆alkyl such as methyl.

Preferably l is 1.

Preferably n is 0 or 1. Ideally n is 0.

Preferably m is 0 or 1. Ideally m is 0.

Preferably R¹ is selected from C₁₋₃alkyl, halo, haloC₁₋₃alkyl andC₁₋₃alkoxy.

In the compounds of formula (I), the carboxylic acid group is suitablyat the ortho position on the benzyl ring. Thus preferred compounds offormula (I) are compounds of formula (II)

where X, Y, Z, Q, A, R¹, R^(2,) R³, m and n are as defined in relationto formula (I).

Furthermore, in compounds of formula (I), the group R²—A— is suitably inthe para position relative to the ring formed by the Y—X—Q—Z— and thenitrogen atom to which they are attached. Thus further preferredcompounds of formula (I) are compounds of formula (III)

where X, Y, Z, Q, A, R¹, R^(2,) R³, m and n are as defined in relationto formula (I).

Particular examples of compounds of formula (I) include the compoundslisted in Table 1 and esters thereof.

TABLE 1 Compound No Structure 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

The use of certain compounds of formula (I) in any medical applicationhas not been described before. Hence, in a further aspect the inventionprovides the use of these particular compounds as medicaments, andpharmaceutical compositions containing them.

Thus the invention provides a compound of formula (IA) which comprises acompound of formula (I) as defined above, provided that

(a) where Q, X, Y and Z together with the nitrogen atom to which theyare attached from a group of formula (i) above, when the group R²—A— isattached at the meta position on the phenylene ring, and A is ethylene,—O(CH₂)— or —(CH₂)S—, R² is other than quinoline optionally substitutedby chloro, or unsubstituted benzothiazol; or

(b) where Q, X, Y and Z together with the nitrogen atom to which theyare attached from a group of formula (i) above, when R³ is methoxy, m is1, the group R²—A— is attached at the para position on the phenylenering, and A is —(CH₂)—, R² is other than indole substituted by—NR⁸C(O)₂R⁹ where R⁸ is hydrogen and R⁹ is alkyl; or for use amedicament.

Suitable compounds of formula (IA) are compounds where Q, X, Y and Ztogether with the nitrogen atom to which they are attached form a groupheterocyclic group other than tetrazole.

In addition, the invention provides a pharmaceutical compositioncomprising a compound of formula (IA) in combination with apharmaceutically acceptable carrier.

Preferred groups within formula (IA) are as set out above in relation toformula (I).

Compounds of formula (IA) are novel and these form a further aspect ofthe invention.

Compounds of formula (I) are either known compounds or they may beprepared using conventional methods. For example, benzoic acid,2-[[5-[3-(2-quinolinylmethoxy)phenyl]-2H-tetrazol-2-yl]methyl]-(9CI)(Compound 37 in Table 1) and its preparation is described by Sawyer, J.Scott; Baldwin, Ronald F.; Rinkema, Lynn E.; Roman, Carlos R.; Fleisch,Jerome H. Optimization of the quinoline and substituted benzyl moietiesof a series of phenyltetrazole leukotriene D4 receptor antagonists. J.Med. Chem. (1992), 35(7), 1200-9. CODEN: JMCMAR; ISSN: 0022-2623. CAN116:174064 CAPLUS.

In particular however, compounds of formula (I) may be prepared byreacting a compound of formula (IV)

where X, Y, Z, Q, A, R¹, m and n are as defined in relation to formula(I); R²⁰ completes an ester group, and so is, for example an alkylgroup, R²¹ is a leaving group; with a compound of formula (V)

R²—H  (V)

where R² is as defined in relation to formula (I) or a precursorthereof, and thereafter, if desired, removing the group R²⁰ to form thecorresponding carboxylic acid.

The reaction is suitably effected in an organic solvent such asdimethylformamide (DMF) in the presence of a base such as an alkalimetal carbonate such as potassium carbonate. Suitable leaving groups forR²¹ include halo such as bromo, mesylate and tosylate.

Any de-esterification is suitably carried out by addition of a base suchas an alkali metal hydroxide such as lithium hydroxide or sodiumhydroxide in the presence of an organic solvent such as an alcohol forinstance, methanol, or trifluoroacetic acid (TFA).

Compounds of formula (IV) are suitably prepared by reacting a compoundof formula (VI)

where X, Y, Z, Q, A, R¹, R³ m and n are as defined in relation toformula (I) and R²⁰ is as defined in relation to formula (V) above, withan appropriate leaving group reagent. For example, where R²¹ is ahalogen group, the compound will be reacted with a halogenating agentsuch as N-bromosuccinimide in the presence of a base such asazoisobutyronitrile (AIBN).

Compounds of formula (VI) where A includes for example heteroatomsspaced from the ring such as nitrogen, may be prepared by reacting acompound of formula (VIA)

where R²⁵ is an alkyl group substituted by a leaving group, with anappropriate primary or secondary amine in particular a monoalkylaminesuch as methylamine. Suitable leaving group substituents for R²⁵ includethose listed above for R²¹. The reaction is suitably effected in anorganic solvent such as an alcohol like ethanol at moderate or depressedtemperatures, for example of from −20° C. to ambient temperature, andconveniently at about 0° C.

Compounds of formula (VI) are suitably prepared by reacting a compoundof formula (VII)

where X, Y, Z, Q, A, R³ and n are as defined in relation to formula (I);with a compound of formula (VIII)

where R¹ and n are as defined in relation to formula (I), R²⁰ is asdefined in relation to formula (VI) and R²² is a leaving group such ashalo, and in particular bromo. The reaction is suitably effected in anorganic solvent such as acetone or DMF, in the presence of a base suchas an alkali metal carbonate for instance potassium carbonate.

Compounds of formula (VII) will be prepared using various methodsdepending upon the precise nature of the heterocyclic ring completed by—Y—X—Q—Z—. These methods would be apparent to the chemist and can bebased upon literature references. For example, where —Y—X—Q—Z— togetherwith the nitrogen atom to which they are attached form a tetrazole ring,these may be prepared by reacting a compound of formula (IX)

where R³, m and A are as defined in relation to formula (I), with anazide such as sodium azide or n-tributyltin azide (n-Bu₃SnN₃). Thereaction may be effected in a solvent such as N-methylpyrrolidine (NMP)in the presence of abase such as triethylamine hydrochloride wherenecessary.

Such a reaction will result in the production of a compound of formula(X)

where R³, m and A are as defined in relation to formula (I). This may beconverted to other compounds of formula (VII) such as pyrazoles byheating the compound with an alkene of formula (XI)

in the presence of a condensation reagent such as Hg(OAc)₂, andthereafter rearranging the product of formula (XII)

where R³, m and A are as defined in relation to formula (I) for exampleby heating to temperatures of from 150 to 200° C., in the presence ofdichlorobenzene (DCB) to yield the corresponding pyrazole of formula(XIII)

Alternatively, pyrazoles can be prepared by reacting a compound offormula Compounds of formula (VIII) and (IX) are either known compoundsof they can be prepared from known compounds using conventional methods.

Alternatively, compounds of formula (I) may be prepared by reacting acompound of formula (XIV)

where X, Y, Z, Q, A, R², R³, m and n are as defined in relation toformula (I); with a compound of formula (VIII) as defined above. Thereaction is suitably effected under conditions similar to thosedescribed for the reaction between compounds of formula (VII) and(VIII).

Compounds of formula (XIV) may be prepared by treating a compound offormula (XV)

where R², R³, A and m are as defined in relation to formula (I) in asimilar manner and with similar reagents to that described above inrelation to the compounds of formula (IX).

In yet a further alternative, compounds of formula (I) where A containsa nitrogen heteroatom may be prepared by reduction of the correspondingamide. Thus for example, compounds of formula (I) where A is a group—NR²⁶CH₂— where R²⁶ is hydrogen or alkyl may be prepared by reduction ofa compound of formula (XVI)

where X, Y, Q, Z, R¹, R², R³, m and n are as defined in relation toformula (I), R²⁰ is as defined in relation to formula (IV) and R²⁶ ishydrogen or alkyl such as methyl, and thereafter, if necessary ordesired, removing any protecting groups R²⁰ for example bydeesterification. Suitably the reaction is effected using a reducingagent such as trichlorosilane in an organic solvent such asdichloromethane. Elevated temperatures, conveniently the refluxtemperature of the solvent are suitably employed. Optionally thereaction is effected in an inert atmosphere, for example in an argonatmosphere. Compounds of formula (XVI) are suitably prepared by reactinga compound of formula (XVII)

where X, Y, Q, Z, R², R³ and m are as defined in relation to formula(I), R²⁶ is as defined in relation to formula (XVI) with a compound offormula (VIII) as defined above, under conditions similar to thosedescribed for the reaction between compounds of formula (VII) and(VIII).

Compounds of formula (XVII) may be obtained by treatment of a compoundof formula (XVIII)

where R², R³ and m are as defined in relation to formula (I) and R²⁶ isas defined in relation to formula (XVI) as described above for thetreatment of compounds of formula (IX).

Compounds of formula (XVIII) are suitable prepared by reacting acompound of formula (XIX)

where R³ and m are as defined above, with an amine of formula (XX)

where R² and R²⁶ are as defined above, using conditions which would bewell known in the art.

Where A contains an oxygen atom directly bonded to the phenyl ring,compounds may be prepared by derivatisation of the corresponding hydroxycompound. Thus compounds of formula (XXI)

where X, Y, Q, Z, R², R³, n and m are as defined in relation to formula(I), R²⁰ is as defined in relation to formula (V), with a compound offormula (XXII)

R²⁷—R²⁸  (XXII)

where R²⁷ is a group such that —OR²⁷ is a group —A—R² as defined inrelation to formula (I) or a precursor thereof, and R²⁸ is a leavinggroup such as halogen, mesylate or tosylate. Reaction conditions aresuitably similar to those described above in relation to the reaction ofcompounds of formula (IV) and (V).

Compounds of formula (XIX) and (XX) are known compounds or they can beprepared from known compounds by conventional methods.

In yet a further alternative method, the compounds of the invention maybe prepared by reacting a compound of formula (XXIII)

where X, Y, Q, Z, R¹ and n are as defined in relation to formula (I),R²⁰ is as defined in relation to formula (V) and R²⁹ is a leaving group,with a compound of formula (XXIV)

where R², R³, A and m are as defined in relation to formula (I) and R³⁰is a boronate derivative,

for example of formula —B(OH)₂ or ; and thereafter if desired ornecessary removing any protecting group R²⁰. Suitable leaving groups forR²⁹ include halogen such as iodine. The reaction is suitably effectedunder an inert atmosphere for example of argon in an organic solventsuch as dimethyl formamide in the presence of a palladium catalyst suchas palladium chloride. The reaction is suitably effected at moderatedtemperatures, for example from 20-100° C., suitably at about 60° C.

Compounds of formula (XXIII) may be prepared by reacting a compound offormula (XXV)

where X, Y, Q and Z are as defined in relation to formula (I) and R²⁹ isas defined in relation to formula (XXIII) with a compound of formula(VIII) as defined above. Reaction conditions are suitably similar tothose described in relation to the reaction between compounds of formula(VII) and (VIII).

Compounds of formula (XXIV) are suitably prepared by reacting a compoundof formula (XXVI)

wherein R², R³, A and m are as defined in relation to formula (I) andR³¹ is a halogen group such as iodine, with appropriate diboron compoundas illustrated hereinafter.

Compounds of formula (XXV) and (XXVI) are either known compounds or theycan be prepared from known compounds by conventional methods.

The compositions of the invention may be in a form suitable for oral use(for example as tablets, lozenges, hard or soft capsules, aqueous oroily suspensions, emulsions, dispersible powders or granules, syrups orelixirs), for topical use (for example as creams, ointments, gels, oraqueous or oily solutions or suspensions), for administration byinhalation (for example as a finely divided powder or a liquid aerosol),for administration by insufflation (for example as a finely dividedpowder) or for parenteral administration (for example as a sterileaqueous or oily solution for intravenous, subcutaneous, intramuscular orintramuscular dosing or as a suppository for rectal dosing).

The compositions of the invention may be obtained by conventionalprocedures using conventional pharmaceutical excipients, well known inthe art. Thus, compositions intended for oral use may contain, forexample, one or more colouring, sweetening, flavouring and/orpreservative agents.

Suitable pharmaceutically acceptable excipients for a tablet formulationinclude, for example, inert diluents such as lactose, sodium carbonate,calcium phosphate or calcium carbonate, granulating and disintegratingagents such as corn starch or algenic acid; binding agents such asstarch; lubricating agents such as magnesium stearate, stearic acid ortalc; preservative agents such as ethyl or propyl p-hydroxybenzoate, andanti-oxidants, such as ascorbic acid. Tablet formulations may beuncoated or coated either to modify their disintegration and thesubsequent absorption of the active ingredient within thegastrointestinal track, or to improve their stability and/or appearance,in either case, using conventional coating agents and procedures wellknown in the art.

Compositions for oral use may be in the form of hard gelatin capsules inwhich the active ingredient is mixed with an inert solid diluent, forexample, calcium carbonate, calcium phosphate or kaolin, or as softgelatin capsules in which the active ingredient is mixed with water oran oil such as peanut oil, liquid paraffin, or olive oil.

Aqueous suspensions generally contain the active ingredient in finelypowdered form together with one or more suspending agents, such assodium carboxymethylcellulose, methylcellulose,hydroxypropylmethylcellulose, sodium alginate, polyvinyl-pyrrolidone,gum tragacanth and gum acacia; dispersing or wetting agents such aslecithin or condensation products of an alkylene oxide with fatty acids(for example polyoxyethylene stearate), or condensation products ofethylene oxide with long chain aliphatic alcohols, for exampleheptadecaethyleneoxycetanol, or condensation products of ethylene oxidewith partial esters derived from fatty acids and a hexitol such aspolyoxyethylene sorbitol monooleate, or condensation products ofethylene oxide with long chain aliphatic alcohols, for exampleheptadecaethyleneoxycetanol, or condensation products of ethylene oxidewith partial esters derived from fatty acids and a hexitol such aspolyoxyethylene sorbitol monooleate, or condensation products ofethylene oxide with partial esters derived from fatty acids and hexitolanhydrides, for example polyethylene sorbitan monooleate. The aqueoussuspensions may also contain one or more preservatives (such as ethyl orpropyl p-hydroxybenzoate, anti-oxidants (such as ascorbic acid),colouring agents, flavouring agents, and/or sweetening agents (such assucrose, saccharine or aspartame).

Oily suspensions may be formulated by suspending the active ingredientin a vegetable oil (such as arachis oil, olive oil, sesame oil orcoconut oil) or in a mineral oil (such as liquid paraffin). The oilysuspensions may also contain a thickening agent such as beeswax, hardparaffin or cetyl alcohol. Sweetening agents such as those set outabove, and flavouring agents may be added to provide a palatable oralpreparation. These compositions may be preserved by the addition of ananti-oxidant such as ascorbic acid.

Dispersible powders and granules suitable for preparation of an aqueoussuspension by the addition of water generally contain the activeingredient together with a dispersing or wetting agent, suspending agentand one or more preservatives. Suitable dispersing or wetting agents andsuspending agents are exemplified by those already mentioned above.Additional excipients such as sweetening, flavouring and colouringagents, may also be present.

The pharmaceutical compositions of the invention may also be in the formof oil-in-water emulsions. The oily phase may be a vegetable oil, suchas olive oil or arachis oil or a mineral oil such as for example liquidparaffin or a mixture of any of these. Suitable emulsifying agents maybe, for example, naturally-occurring gums such as gum acacia or gumtragacanth, naturally-occurring phosphatides such as soya bean,lecithin, an esters or partial esters derived from fatty acids andhexitol anhydrides (for example sorbitan monooleate) and condensationproducts of the said partial esters with ethylene oxide such aspolyoxyethylene sorbitan monooleate. The emulsions may also containsweetening, flavouring and preservative agents.

Syrups and elixirs may be formulated with sweetening agents such asglycerol, propylene glycol, sorbitol, aspartame or sucrose, and may alsocontain a demulcent, preservative, flavouring and/or colouring agent.

The pharmaceutical compositions may also be in the form of a sterileinjectable aqueous or oily suspension, which may be formulated accordingto known procedures using one or more of the appropriate dispersing orwetting agents and suspending agents, which have been mentioned above. Asterile injectable preparation may also be a sterile injectable solutionor suspension in a non-toxic parenterally-acceptable diluent or solvent,for example a solution in 1,3-butanediol.

Suppository formulations may be prepared by mixing the active ingredientwith a suitable non-irritating excipient which is solid at ordinarytemperatures but liquid at the rectal temperature and will thereforemelt in the rectum to release the drug. Suitable excipients include, forexample, cocoa butter and polyethylene glycols.

Topical formulations, such as creams, ointments, gels and aqueous oroily solutions or suspensions, may generally be obtained by formulatingan active ingredient with a conventional, topically acceptable, vehicleor diluent using conventional procedure well known in the art.

Compositions for administration by insufflation may be in the form of afinely divided. powder containing particles of average diameter of, forexample, 30μ or much less, the powder itself comprising either activeingredient alone or diluted with one or more physiologically acceptablecarriers such as lactose. The powder for insufflation is thenconveniently retained in a capsule containing, for example, 1 to 50 mgof active ingredient for use with a turbo-inhaler device, such as isused for insufflation of the known agent sodium cromoglycate.

Compositions for administration by inhalation may be in the form of aconventional pressurised aerosol arranged to dispense the activeingredient either as an aerosol containing finely divided solid orliquid droplets. Conventional aerosol propellants such as volatilefluorinated hydrocarbons or hydrocarbons may be used and the aerosoldevice is conveniently arranged to dispense a metered quantity of activeingredient.

For further information on Formulation the reader is referred to Chapter25.2 in Volume 5 of Comprehensive Medicinal Chemistry (Corwin Hansch;Chairman of Editorial Board), Pergamon Press 1990.

The amount of active ingredient that is combined with one or moreexcipients to produce a single dosage form will necessarily varydepending upon the host treated and the particular route ofadministration. For example, a formulation intended for oraladministration to humans will generally contain, for example, from 0.5mg to 2 g of active agent compounded with an appropriate and convenientamount of excipients which may vary from about 5 to about 98 percent byweight of the total composition. Dosage unit forms will generallycontain about 1 mg to about 500 mg of an active ingredient. For furtherinformation on Routes of Administration and Dosage Regimes the reader isreferred to Chapter 25.3 in Volume 5 of Comprehensive MedicinalChemistry (Corwin Hansch; Chairman of Editorial Board), Pergamon Press1990.

The size of the dose for therapeutic or prophylactic purposes of acompound of the Formula I will naturally vary according to the natureand severity of the conditions, the age and sex of the animal or patientand the route of administration, according to well known principles ofmedicine. In particular, compounds of formula (I) and compositionscontaining them will be used in the treatment of diabetes.

Thus in yet a further aspect, the invention provides a method oftreating diabetes which comprises administering to a patient aneffective amount of a compound of formula (I) as defined above.

The invention will now be particularly described by way of example.

EXAMPLES Example 1 Preparation of2-(2-carboxybenzyl)-5-[3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethyl]phenyltetrazole(Compound 23 in Table 1)

Step 1

5-(3-methoxy-4-methyl)phenyltetrazole

A mixture of 3-methoxy-4-methylbenzonitrile (1.47 g, 10 mmol),triethylamine hydrochloride (2.1 g, 15 mmol) and sodium azide (2.0 g, 30mmol) in 1-methyl-2-pyrrolidinone (20 ml) was stirred at 150° C. for 3hours. The mixture was cooled, diluted with water (30 ml) and acidifiedwith 2M hydrochloric acid (30 ml). The resulting precipitate wascollected by filtration, washed with water and dried to afford therequired product (1.9 g). NMR d (d₆-DMSO) 2.2 (3H, s), 3.88 (3H, s),7.35 (1H, d), 7.55 (2H, m); MS[MH]⁺ 191

Step 2

2-(2-carbomethoxybenzyl)-5-(3-methoxy-4-methyl)phenyltetrazole

A mixture of 5-(3-methoxy-4-methyl)phenyltetrazole (760 mg, 4 mmol),2-carbomethoxybenzyl-bromide (788 mg, 4 mmol), potassium carbonate (1.38g, 10 mmol) and potassium iodide (20 mg) in acetone (50 ml) was stirredunder reflux for 16 hours. The acetone was evaporated under reducedpressure and the residue was partitioned between water and ethylacetate. The organic layer was washed with water, dried over anhydrousmagnesium sulphate, filtered and evaporated to a gum. This was purifiedby flash column chromatography on a Varian 20 g silica megabondelutcolumn eluting with 5% v/v to 20% v/v ethyl acetate in isohexane toobtain the title compound (700 mg). NMR d (d₆-DMSO) 2.2 (3H, s), 3.8(3H, s), 3.84 (3H, s), 6.25 (2H, s), 7.25 (2H, d), 7.5 (3H, m), 7.62(1H, t), 7.97 (1H, d); MS[MH]⁺ 339.

Step 3

2-(2-carbomethoxybenzyl)-5-(4-bromomethyl-3-methoxy)phenyltetrazole

A mixture of2-(2-carbomethoxybenzyl)-5-(3-methoxy-4-methyl)phenyltetrazole (676 mg,2 mmol), N-bromosuccinimide (390 mg, 2.2 mmol) and benzoyl peroxide (30mg) in carbon tetrachloride (30 ml) was stirred under reflux for 3hours. The reaction mixture was cooled to ambient temperature and washedwith water (2×30 ml). The organic extract was dried over anhydrousmagnesium sulphate, filtered and concentrated under reduced pressure toleave the title compound (880 mg). NMR d (d₆-DMSO) 3.8 (3H, s), 3.95(3H, s), 4.63 (2H, s), 6.5 (2H, s), 7.3 (1H, t), 7.6 (5H, m), 7.95 (1H,d); MS[MH]+ 417/419.

Step 4

2-(2-carbomethoxybenzyl)-5-[3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethyl]phenyltetrazole

A mixture of2-(2-carbomethoxybenzyl)-5-(4-bromomethyl-3-methoxy)phenyltetrazole (209mg, 0.5 mmol), 2-methylaminopyridine (108 mg, 1.0 mmol), potassiumcarbonate (280 mg, 2.0 mmol) and potassium iodide (84 mg, 0.5 mmol) inN,N-dimethylacetamide (10 ml) was stirred at ambient temperature for 16hours. The reaction mixture was diluted with water (50 ml) and extractedwith ethyl acetate. The organic extract was washed with water, driedover anhydrous magnesium sulphate, filtered and the solvent removedunder reduced pressure. The residue was purified by flash columnchromatography on Varian 20 g silica megabondelut column eluting with10% v/v to 20% v/v ethyl acetate in isohexane to obtain the titlecompound (90 mg). MS[MH]⁺ 445.

Step 5

Compound 23

A mixture of2-(2-carbomethoxybenzyl)-5-[3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethyl]phenyltetrazole(90 mg, 0.2 mmol) and 1M aqueous lithium hydroxide (1 ml, 1 mmol) inmethanol (10 ml) was stirred under reflux for 1 hour. The mixture wascooled, diluted with water (30 ml) and acidified with 2M hydrochloricacid (10 ml). The resulting mixture was washed with ethyl acetate andthe aqueous layer was evaporated under reduced pressure to leave theproduct as the hydrochloride salt (20 mg). NMR d (d₆-DMSO) 3.19 (3H, s),3.89 (3H, s), 4.82 (2H, s), 6.3 (2H, s), 6.9 (1H, t), 7.2 (2H, t), 7.27(1H, d), 7.52 (1H, t), 7.6 (3H, m), 8.0 (3H, m); MS[MH]⁺ 431

Example 2

Using the appropriate cyanotoluene in place of 2-methoxy-4-cyanotolueneand the appropriate amine in place of 2-methylaminopyridine, theadditional examples in Table 2 were prepared using the methodillustrated above in Example 1.

The starting materials are either commercially available or wereprepared according to the literature reference (cited in Table 2) orwere prepared as described below:

TABLE 2 Compd cyanotoluene amine MS no. (lit. Reference) (lit reference)(MH)⁺ NMR δ (d₆-DMSO) 9 3-cyanobenzylbromide 2-n-Butylbenzimidazole 4670.9(3H, t), 1.3(2H, m), 1.7(2H, m) ex. Aldrich JACS (1937), 59 3.17(2H,t), 5.82(2H, s), 6.3(2H, s), 178 7.2(1H, d), 7.32(1H, d), 7.57(5H, m),7.81(2H, d), 7.98(1H, s), 8.0(2H, d); 10 4-cyanobenzylbromide2-methylaminopyridine 401 3.2(3H, s), 4.97(2H, s), 6.3(2H, s), ex.Aldrich ex. Aldrich 6.9(1H, t), 7.2(2H, t), 7.41(2H, d), 7.5(1H, t),7.6(1H, t), 8.0(5H, m); 12 4-cyanobenzylbromide indoline 412 2.88(2H,t), 3.25(2H, t), 4.32(2H, s), ex. Aldrich ex. Aldrich 6.3(2H, s),6.57(2H, m), 6.97(1H, t), 7.02(1H, d), 7.2(1H, d), 7.57(4H, m), 8.0(3H,m); 15 4-cyanobenzylbromide 2-n-Butylbenzimidazole 467 0.8(3H, t),1.32(2H, m), 1.66(2H, m), ex. Aldrich JACS (1937), 59 2.8(2H, t),5.53(2H, s), 6.3(2H, s), 178 7.1(3H, d), 7.2(2H, d), 7.5(4H, m),7.97(3H, m); 16 4-cyanobenzylbromide ex. Aldrich

468 0.88(3H, t), 1.32(2H, m), 1.8(2H, m), 3.02(2H, t), 6.1(2H, s),6.3(2H, s), 7.2(1H, d), 7.5(1H, t), 7.6(1H, t), 7.63(2H, d), 7.78(1H,t), 8.0(3H, m), 8.61(1H, d), 9.0(1H, d); 21 3-cyanobenzylbromide2-methylaminopyridine 401 5.0(2H, s), 6.3(2H, s), 6.83(1H, t), ex.Aldrich ex. Aldrich 7.1(1H, m), 7.22(1H, d), 7.39(1H, d), 7.6(3H, m),7.82(1H, t), 7.98(3H, m), 8.03(1H, d); 22 3-cyanobenzylbromidebenzimidazole 411 5.8(2H, s), 6.3(2H, s), 7.2(1H, d), ex. Aldrich ex.Aldrich 7.57(6H, m), 7.85(2H, m), 8.0(2H, m), 8.19(1H, s), 9.7(1H, s);24 2-methoxy-4-cyanotoluene benzimidazole 441 3.9(3H, s), 5.7(2H, s),6.3(2H, s), JCS (C), (1969) 183 ex. Aldrich 7.2(1H, d), 7.6(7H, m),7.85(2H, m), 7.98(1H, d), 9.6(1H, s); 26 4-cyanobenzylbromide2-Methylaminobenzoxazole 441 3.1(3H, s), 4.8(2H, s), 6.3(2H, s), ex.Aldrich JCS (1934) 1186-1190 7.0(1H, t), 7.13(1H, t), 7.22(1H, d),7.28(1H, d), 7.4(1H, d), 7.5(2H, d), 7.57(2H, t), 8.0(3H, m); 274-cyanobenzylbromide 2-methylamino-5-bromopyridine 479/481 3.05(3H, s),4.82(2H, s), 6.3(2H, s), ex. Aldrich JOC (1983) 48 6.7(1H, d), 7.2(1H,d), 7.35(2H, d), 1064 7.57(2H, m), 7.68(1H, dd), 7.95(3H, m), 8.13(1H,d); 29 4-cyanobenzylbromide 2-methylamino-5-phenylpyridine 477 3.25(3H,s), 5.0(2H, s), 6.3(2H, s), ex. Aldrich Heterocyles 7.2(2H, m), 7.39(1H,t), 7.5(6H, m), (1986) 24 (7), 7.65(2H, d), 8.0(3H, t), 8.18(1H, t),1815 8.3(1H, s); 38 2-methoxy-4-cyanotoluene2-methylamino-5-phenylpyridine 507 3.2(3H, s), 3.9(3H, s), 4.85(2H, s),JCS (C), (1969) 183 Heterocyles 6.3(2H, s), 7.1(1H, m), 7.2(1H, d),(1986) 24 (7), 7.25(1H, d), 7.35(1H, d), 7.46(3H, m), 1815 7.6(5H, m),7.98(1H, d), 8.5(1H, d), 8.26(1H, s); 39 2-methoxy-4-cyanotoluene2-aminopyridine 417 3.9(3H, s), 4.6(2H, d), 6.3(2H, d), JCS (C), (1969)183 ex. Aldrich 6.8(1H, m), 7.1(2H, m), 7.5(5H, m), 7.9(3H, m) 412-bromo-4-cyanotoluene 2-methylaminopyridine 479/481 4.9(2H, s),6.32(2H, s), 6.85(1H, m), J. Prakt. Chem. (1889) ex. Aldrich 7.0(1H, m),7.25(2H, m), 7.56(2H, m), 39 487 7.83(1H, m), 7.98(2H, m), 8.05(1H, d),8.2(1H, s); 13 4-cyanobenzylbromide benzimidazole 411 5.8(2H, s),6.3(2H, s), 7.2(1H, d), ex. Aldrich ex. Aldrich 7.55(6H, m), 7.82(2H,m), 8.0(3H, m), 9.68(1H, s); 14 4-cyanobenzylbromide indoline 4105.45(2H, s), 6.3(2H, s), 6.48(1H, s), ex. Aldrich ex. Aldrich 7.02(2H,m), 7.2(1H, s), 7.3(2H, d), 7.4(1H, d), 7.5(4H, m), 7.95(3H, br d); 404-cyanobenzylbromide 2-n-butylaminopyridine 443 0.85(3H, t), 1.3(2H, m),1.5(2H, m), ex. Aldrich Hererocycles 3.45(2H, t), 4.8(2H, s), 6.34(2H,s), (1988) 27 319 6.52(2H, m), 7.02(1H, d), 7.35(2H, d), 7.42(3H, m),7.93(3H, m), 8.05(1H, m); 28 3-chloro-4-methylbenzonitrile2-methylaminopyridine 435/437 3.2(3H, s), 4.95(2H, s), 6.3(2H, s), ex.Aldrich ex. Aldrich 6.85(1H, t), 7.03(1H, d), 7.22(1H, d), 7.35(1H, d),7.5(1H, t), 7.58(1H, t), 7.83(1H, br t), 7.92(1H, d), 7.98(1H, d),8.05(2H, m);

Example 32-(2-Carboxybenzyl)-5-[3-methoxy-4-(N-tert-butoxycarbonyl-N-methyl)aminomethyl]phenyltetrazole(Compound 45 in Table 1)

Step 1

2-(2-Carboethoxybenzyl)-5-[3-methoxy-4-(N-methyl)aminomethyl]phenyltetrazole

2-(2-Carboethoxybenzyl)-5-(4-bromomethyl-3-methoxy)phenyltetrazole(15.53 g, 36.0 mmol) was stirred in a solution of methylamine in ethanol(33% w/v) (175 ml) at −5° C. for 30 minutes. The solution was warmed to0° C. for 1 hour before being concentrated under reduced pressure. Theresidue was partitioned between water and dichloromethane. Thedichloromethane was washed with water before being dried over magnesiumsulphate and filtered. The organic phase was concentrated under reducedpressure to afford the title compound (10.25 g, 75%) as an orange oil,which was used without further purification. NMR d_(H) (CDCl₃) 1.4 (3H,t), 2.5 (3H, s), 4.0 (3H, s), 4.1 (2H, s), 4.4 (2H, q), 6.3 (2H, s), 6.9(1H, d), 7.5 (3H, m), 7.7 (2H, m), 8.1 (1H, m). MS [MS]⁺ 382

Step 2

2-(2-Carboethoxybenzyl)-5-[3-methoxy-4-(N-tert-butoxycarbonyl-N-methyl)aminomethyl]phenyltetrazole

Di-tert-butyl dicarbonate (126 mg, 0.58 mmol) was added to a solution of2-(2-Carboethoxybenzyl)-5-[3-methoxy-4-(N-methyl)aminomethyl]phenyltetrazole(200 mg, 0.52 mmol) and triethylamine (0.08 ml, 0.58 mmol) indichloromethane (5 ml). The mixture was stirred at ambient temperaturefor 2 hours. Water (5 ml) was added, and the mixture was extracted withdichloromethane. The organic phase was dried over magnesium sulfate,filtered and concentrated under reduced pressure. The residue waspurified by flash column chromatography using a Varian silicamegabondelut column, using ethyl acetate-isohexane (1:9) as the eluent,to yield the title compound (132 mg, 52%) as a colourless oil. NMR d_(H)(CDCl₃) 1.4 (12H, m), 2.9 (3H, br), 3.9 (3H, s), 4.4 (2H, q), 4.5 (2H,br), 6.3 (2H, s), 6.9 (1H, d), 7.2 (1H, m), 7.4 (2H, m), 7.6 (2H, s),7.7 (1H, d), 8.1 (1H, dd). MS [MS]⁺ 482

Step 3

Compound 45

2-(2-Carboethoxybenzyl)-5-[3-methoxy-4-(N-tert-butoxycarbonyl-N-methyl)aminomethyl]phenyltetrazole(132 mg, 0.27 mmol) was dissolved in ethanol (4 ml) containing aqueous1.0 M lithium hydroxide (0.55 ml, 0.55 mmol). The mixture was heatedunder reflux for 1 hour before the addition of c.HCl (0.11 ml). Thesolution was concentrated under reduced pressure and the residue wasdried, on azeotroping with toluene, to afford the title compound (102mg, 76%) as a yellow solid. NMR d_(H) (d₆-DMSO) 1.4 (9H, m), 2.8 (3H,s), 3.9 (3H, s), 4.4 (2H, s), 6.3 (2H, s), 7.2 (3H, m), 7.6 (3H, m), 8.0(1H, m). MS [MH]⁺ 454

Example 4

Using the appropriate chloride precursor in place oft-butylchloroformate in Example 2, the additional examples in Table 3were prepared using the method of Example 3.

TABLE 3 Compd NMR δ no. precursor (MH)⁺ (d₆-DMSO) 46

522 2.3(3H, s), 3.9(5H, m), 4.8(2H, s), 6.3(2H, s), 6.9-7.7(10H, m),8.0(1H, m) 47

478 1.0-1.8(13H, m), 2.2(3H, s), 3.9(3H, m), 4.5(2H, d), 6.3(2H, s),7.2(3H, m), 7.6(3H, m), 8.0(1H, m) 11

454

Example 52-[[5-[4-[[6-[(Butoxycarbonyl)amino]-1H-indol-1-yl]methyl]-3-methoxyphenyl]-2H-tetrazol-2-yl]methyl]-benzoicacid (Compound 1 in Table 1)

Step 1

A mixture of Carbamic acid,[1-[[2-methoxy-4-(1H-tetrazol-5-yl)phenyl]methyl]-1H-indol-6-yl]-, butylester (150 mg.0.36 mmol), ethyl(2-bromomethyl)benzoate (104 mg.0.43mmol), potassium carbonate (60 mg.0.43 mmol) and potassium iodide(10 mg)in acetone (20 ml.) was heated and stirred at 60° C. for 4 hours. Themixture was filtered and the filtrate was evaporated. The residue wasdissolved in ethyl acetate and washed twice with water, dried(MgSO₄) andevaporated. The resulting oil was columned (Varian Megabondelut silica)run in a gradient of 100% dichloromethane to 80% dichloromethane/20%ethyl acetate. Two isomers were isolated:—the least polar—2-tetrazole)(100 mg.) NMRd(CDCl₃)0.95(t,3H),1.2(t,3H),1.4(m,2H),1.6(m,2H),3.4(m,1H),3.95(s,3H),4.15(t,2H),4.4(m,2H),5.3(s,2H),6.3(s,2H),6.5(d,1H),6.65(m,1H),6.8(d,1H),6.9(m,2H),7.1(d,1H),7.4(m,3H),7.65(m,2H),8.05(m,1H)MS583[MH]⁺

and the most polar—(1-tetrazole) (20 mg.) NMd(CDCl₃)0.95(t,3H),1.2(t,3H),1.4(m,2H),1.6(m,2H),3.4(m,1H),3.8(s,3H),4.15(t,2H),4.4(m,2H),5.3(s,2H),6.1(s,2H),6.5(d,1H),6.65(m,1H),6.8(d,1H),6.9(m,2H),7.1(d,1H),7.4(m,3H),7.65(m,2H),8.05(m,1H)MS583[MH]⁺

Step 2

A mixture of the 2-(ethyl 2-benzyl carboxylate)tetrazole (the leastpolar product from step 1) (100 mg, 0.17 mmol) and 1M aqueous lithiumhydroxide (1 ml, 1 mmol) in ethanol(10 ml.) was stirred at ambienttemperature for 8 hours. The mixture was then acidified to pH1 using 2Mhydrochloric acid and after dilution with water, the solid precipitatewas collected and washed. (32 mg.) NMR d (d₆-DMSO)(0.9(t,3H),1.4(m,2H),1.6(m,2H),3.95(s,3H),4.0(m,2H),5.3(s,2H),6.3(s,2H),6.4(m,1H),6.8(m,1H),7.0(m,1H),7.2(m,1H),7.35(m,1H),7.4(m,1H),7.6(m,5H),8.0(m,1H),9.4(s,1H).MS553[MH]⁻

Example 6

2-[[5-[4-[[6-[(Butoxycarbonyl)amino]-1H-indol-1-yl]methyl]-3-methoxyphenyl]-1H-tetrazol-1-yl]methyl]-benzoicacid (Compound no 2 in Table 1) A mixture of the 1-(ethyl 2-benzylcarboxylate)tetrazole (the most polar isomer produced in Example 5step 1) (20 mg, 0.034 mmol) and 1M aqueous lithium hydroxide (0.2 ml,0.2 mmol) in ethanol(2 ml.) was stirred at ambient temperature for 8hours. The mixture was then acidified to pH1 using 2M hydrochloric acidand after dilution with water, the solid precipitate was collected andwashed. (6 mg.).MS553[MH]⁻

Example 7

Using the appropriate tetrazole precursor in place of the carbamic acid,[1-[[2-methoxy-4-(1H-tetrazol-5-yl)phenyl]methyl]-1H-indol-6-yl]-, butylester, used in Example 5, the Compounds listed in Table 4 were preparedusing a method analogous to that of Example 5

The tetrazole precursors were prepared according to the literature ((1)Yee, Ying K; Bernstein, Peter R.; Adams, Edward J.; Brown, Frederick J.;Cronk, Laura A.; Hebbel, Kevin C.; Vacek, Edward P.; Krell, Robert D.;Snyder, David W. A novel series of selective leukotriene antagonists:exploration and optimization of the acidic region in 1,6-disubstitutedindoles and indazoles. J. Med. Chem (1990), 33(9), 2437-51; (2) Brown,Frederick Jeffrey, Bernstein, Peter Robert; Yee, Ying Kwong.Heterocyclic amides. Eur. Pat. Appl. EP179619 A1) or were prepared asdescribed below:

TABLE 4 Compound No precursor MS (MH)⁻ NMR δ (d₆-DMSO) 5

566 (CDCl3) 1.8(m, 8H), 3.7(s, 3H), 4.0(s, 2H), 4.05(m, 1H), 5.6(s, 2H),6.85(m, 4H), 7.4(m, 1H), 7.6(m, 3H), 8.0(m, 3H) 6

565 1.0(m, 2H), 1.15(m, 4H), 1.2(m, 2H), 3.2(s, 3H), 3.7(m, 3H), 6.0(s,2H), 6.8(m, 2H), 7.2(m, 8H), 7.5(m, 1H), 7.7(m, 1H)

Example 81-(2-carboxybenzyl)-3-(3-bromo-4-methyl-N-2-pyridyl)aminomethyl)phenylpyrazole(Compound 43 in Table 1)

Step 1

5-(3-bromo-4-methyl)phenyltetrazole

A mixture of 3-bromo-4-methylbenzonitrile (8.8 g, 45 mmol),triethylamine hydrochloride (9.3 g, 67.5 mmol) and sodium azide (8.8 g,135 mmol) in 1-methyl-2-pyrrolidinone (60 ml) was stirred at 150° C. for3 hours. The reaction mixture was cooled to ambient temperature andacidified with 2M hydrochloric acid. After stirring for 15 minutes, themixture was filtered and the residue washed with water and dried to givethe title compound (9.2 g). NMR d (d₆-DMSO) 2.4 (3H, s), 7.58 (1H, d),7.95 (1H, d), 8.2 (1H, s); MS [MH]⁺ 239/241.

Step 2

1-vinyl-5-(3-bromo-4-methyl)phenyltetrazole

A mixture of 5-(3-bromo-4-methyl)phenyltetrazole (2.4 g, 10 mmol),mercuric acetate (50 mg) and 2 drops of concentrated sulphuric acid invinyl acetate (8.0 ml) was heated under reflux for 2 hours. The excessvinyl acetate was then evaporated under reduced pressure, and theresidue was purified by flash column chromatography on a Varian 20 gsilica megabondelut column, eluting with 5% v/v ethyl acetate inisohexane, to give the title compound (2.0 g) NMR d (d₆-DMSO) 2.5 (3H,s), 5.4 (1H, dd), 6.25 (1H, dd), 7.37 (1H, d), 7.55 (1H, q), 8.02 (1H,dd), 8.39 (1H, s); MS [MH]⁺265/267.

Step 3

3-(3-bromo-4-methyl)phenylpyrazole

1-vinyl-5-(3-bromo-4-methyl)phenyltetrazole was heated under reflux in2-dichlorobenzene (60 ml) for 8 hours. The dichlorobenzene was thenremoved under reduced pressure and the residue was purified by flashcolumn chromatography on a 50 g silica Isolute column, eluting withethyl acetate, to give the title compound (1.7 g). NMR d (d₆-DMSO) 2.32(3H, s), 6.74 (1H, s), 7.38 (1H, d), 7.7 (2H, m), 8.0 (1H, s), 12.9 (1H,br); MS [MH]⁺ 237/239.

Step 4

1-(2-carboethoxybenzyl)-3-(3-bromo-4-methyl)phenylpyrazole

A mixture of 3-(3-bromo-4-methyl)phenylpyrazole (1.7 g, 7.17 mmol),2-carboethoxybenzyl bromide (1.74 g, 7.17 mmol) and potassium carbonate(4.9 g, 35.8 mmol) in acetone (50 ml) was stirred under reflux for 16hours. A further 0.87 g (3.59 mmol) of 2-carboethoxybenzyl bromide wasadded and mixture stirred under reflux for a further 24 hours. Theacetone was removed by distillation under reduced pressure and theresidue was partitioned between water and ethyl acetate. The ethylacetate extract was dried over anhydrous magnesium sulphate, filteredand evaporated. The residue was purified by flash column chromatographyon a 20 g Varian silica megabondelut column, eluting with 5% v/v to 10%v/v ethyl acetate in isohexane, to leave the title compound (2.2 g). NMRd (d₆-DMSO) 1.35 (3H, t), 2.37 (3H, s), 4.34 (2H, q), 5.7 (2H, ), 5.79(1H, d), 6.85 (1H, d), 7.33 (1H, d), 7.4 (1H, t), 7.5 (1H, t), 7.64 (1H,d), 7.81 (1H, d), 7.9 (1H, d), 7.97 (1H, d); MS [MH]⁺ 399/401.

Step 5

1-(2-carboethoxybenzyl)-3-(3-bromo-4-bromomethyl)phenylpyrazole

A mixture of 1-(2-carboethoxybenzyl)-3-(3-bromo-4-methyl)phenyltetrazole(2.1 g, 5.26 mmol), N-bromosuccinimide (1.07 g, 6.0 mmol) and benzoylperoxide (100 mg) in carbon tetrachloride (50 ml) was stirred underreflux for 16 hours. The mixture was cooled and washed with water (3×20ml), dried over anhydrous magnesium sulphate, filtered and evaporated toleave the crude product as a solid (3.1 g). NMR d (d₆-DMSO) 1.34 (3H,t), 4.35 (2H, q), 4.75 (2H, s), 5.72 (2H, s), 6.83 to 8.0 (9H,aromatics); MS [MH]⁺ 477/479/481

Step 6

1-(2-carboethoxybenzyl)-3-(3-bromo-4-methylaminomethyl)phenylpyrazole

1-(2-carboethoxybenzyl)-3-(3-bromo-4-bromomethyl)phenyltetrazole (1.1 g)was stirred in 33% ethanolic methylamine solution (50 ml) for 6 hours.The ethanol was removed by evaporation and the residue was partitionedbetween ethyl acetate and saturated sodium carbonate solution. The ethylacetate extract was dried over anhydrous magnesium sulphate, filteredand evaporated to an oil. This oil was purified by flash columnchromatography on a Varian 20 g silica megabondelut column, eluting withethyl acetate followed by 10% ethanol in ethyl acetate and finally 10%ethanol in ethyl acetate containing 1% of triethylamine, to give theproduct (290 mg). NMR d (d₆-DMSO) 1.4 (3H, t), 2.42 (3H, s), 3.82 (2H,s), 4.4 (2H, q), 5.8 (2H, s), 6.59 (1H, d), 6.9 (1H, d), 7.4 (4H, m),7.7 (1H, dd), 8.01 (2H, m); MS [MH]⁺ 477/479/481

Step 7

1-(2-carboethoxybenzyl)-3-[3-bromo-4-(N-methyl-N-2-pyridyl)aminomethyl]pyrazole

A mixture of1-(2-carboethoxybenzyl)-3-(3-bromo-4-methylaminomethyl)phenyltetrazole(280 mg, 0.65 mmol) and N,N-diisopropylamine (0.5 ml) in2-fluoropyridine (10 ml) was stirred under reflux in an inert atmospherefor 48 hours. The excess 2-fluoropyridine was evaporated under reducedpressure and the residue was partitioned between ethyl acetate andsaturated sodium carbonate solution. The ethyl acetate extract was driedover anhydrous magnesium sulphate, filtered and evaporated to dryness.The residue was purified by flash column chromatography on a Varian 20 gsilica megabondelut column, eluting with 20% ethyl acetate in isohexane,to give the title compound (200 mg). NMR d (d₆-DMSO) 1.4 (3H, t), 3.15(3H, s), 4.4 (2H, q), 4.8 (2H, s), 5.8 (2H, s), 6.43 (1H, d), 6.58 (2H,m), 6.85 (1H, d), 7.07 (1H, d), 7.4 (4H, m), 7.62 (1H, d), 8.01 (1H, d),8.03 (1H, s), 8.19 (1H, d); MS [MH]⁺ 505/507.

Step 8

(Compound 43)

A mixture of1-(2-carboethoxybenzyl)-3-[3-bromo-4-(N-methyl-N-2-pyridyl)aminomethyl]phenylpyrazole(190 mg, 0.375 mmol) and 2M aqueous lithium hydroxide solution (0.5 ml,0.5 mmol) in ethanol (10 ml) was stirred under reflux for 2 hours. Themixture was cooled to ambient temperature and neutralised with 1Maqueous hydrochloric acid. The solution was concentrated under reducedpressure. The residue was purified by flash column chromatography on aVarian 20 g silica megabondelut eluting with 5% v/v to 10% v/v ethylacetate in isohexane to obtain the title compound (140 mg). NMR d(d₆-DMSO) 3.03 (3H, s), 4.79 (2H, s), 5.75 (2H, s), 6.6 (2H, m), 6.78(2H, m), 7.0 (1H,d), 7.39 (1H, t), 7.5 (2H, m), 7.66 (1H, d), 7.82 (1H,d), 7.9 (1H, d), 8.0 (1H, s), 8.03 (1H, d); MS [MH]⁺ 477/479.

Example 9 Preparation of Compound 36 in Table1—1-(2-Carboxy)benzyl-3-[3-chloro-4-(N-methyl-N-2-pyridyl)aminomethyl]phenylpyrazole

Step 1

5-(3-Chloro-4-methyl)phenyltetrazole

3-Chloro-4-methylbenzonitrile (1.51 g, 10 mmol) was dissolved inN-methylpyrrolidione (20 ml) containing triethylamine hydrochloride(2.05 g, 15 mmol) and sodium azide (1.95 g, 30 mmol). The solution washeated at 155° C. for 5 hours before being cooled and diluted with water(40 ml). The mixture was acidified using dilute hydrochloric acid (3.0M, 20 ml). The precipitate formed was filtered off and washed with waterbefore being dried to yield the title compound (2.05 g) which was usedwithout further purification. MS [MH]⁺ 195 NMR d_(H) (d₆-DMSO) 2.4 (3H,s), 7.6 (1H, d), 7.9 (1H, d), 8.0 (1H, s).

Step 2

2-Vinyl-5-(3-chloro-4-methyl)phenyltetrazole

5-(3-Chloro-4-methyl)phenyltetrazole (582 mg, 3 mmol), was dissolved invinyl acetate (2.5 ml) containing mercury(II) acetate (20 mg) andcatalytic concentrated sulfuric acid (1 drop). The mixture was heated,under argon, at 100° C. for approximately 16 hours before being cooled.The mixture was purified by flash column chromatography, using ethylacetate-iso-hexane (10:90) as eluent, to afford the title compound (530mg, 80%). MS [MH]⁺ 220 NMR d_(H) (d₆-DMSO) 2.4 (3H, s), 5.6 (1H, d), 6.2(1H, d), 7.5 (1H, d), 7.9 (2H, m), 8.0 (1H, s).

Step 3

3-(3-chloro-4-methyl)phenylpyrazole

2-Vinyl-5-(3-chloro-4-methyl)phenyltetrazole (370 mg, 1.7 mmol) washeated at 180° C. in 1,2-dichlorobenzene (25 ml) for approximately 16hours. The mixture was concentrated under reduced pressure to afford thetitle compound (246 mg, 76%) as a pink solid. MS [MH]⁺ 193 NMR d_(H)(d₆-DMSO) 2.3 (3H, s), 6.7 (1H, s), 7.3 (1H, d), 7.7 (2H, m), 7.8 (1H,s), 12.9 (1H, br).

Step 4

1-(2-Carbomethoxy)benzyl-3-(3-chloro-4-methyl)phenylpyrazole

3-(3-Chloro-4-methyl)phenylpyrazole (230 mg, 1.2 mmol) was dissolved inacetone (5 ml) containing 2-carbomethoxybenzyl bromide (365 mg, 1.6mmol), potassium carbonate (200 mg) and potassium iodide (catalytic).The mixture was heated at 60° C. for approximately 16 hours before beingconcentrated under reduced pressure. The residue was purified by flashcolumn chromatography, using ethyl acetate-iso-hexane (10:90 increasingto 25:75) as eluent, to yield the title compound (326 mg, 80%). MS [MH]⁺341 NMR d_(H) (d₆-DMSO) 2.3 (3H, s), 3.9 (3H, s), 5.7 (2H, s), 6.8 (1H,d), 6.9 (1H, d), 7.3 (1H, m), 7.4 (1H,m), 7.5 (1H, m), 7.6 (1H, m), 7.8(1H, s), 7.9 (2H, m).

Step 5

1-(2-Carbomethoxy)benzyl-3-(3-chloro-4-bromomethyl)phenylpyrazole

1-(2-Carbomethoxy)benzyl-3-(3-chloro-4-methyl)phenylpyrazole (320 mg,0.9 mmol) was taken up in carbon tetrachloride (10 ml) containingN-bromosuccinimide (184 mg, 1.0 mmol). The mixture was heated to 70° C.and AIBN (20 mg) was added. The temperature was increased to 90° C. for4.5 hours and the solution was cooled and filtered. The filtrate waswashed with water and the organic phase was dried with magnesiumsulfate, filtered and concentrated under reduced pressure to afford thetitle compound (600 mg) which was used without further purification. MS[MH]⁺ 421.

Step 6

1-(2-Carbomethoxy)benzyl-3-[3-chloro-4-(N-methyl-N-2-pyridyl)aminomethyl]phenylpyrazole

1-(2-Carbomethoxy)benzyl-3-(3-chloro-4-bromomethyl)phenylpyrazole (600mg, 1.4 mmol) was added to a solution of 2-(N-methyl)aminopyridine (0.14ml, 1.4 mmol) containing potassium carbonate (386 mg) and catalyticpotassium iodide. The mixture was stirred at ambient temperature forapproximately 16 hours before being poured onto water. The mixture wasextracted using diethyl ether and the combined organic extracts werewashed with water and brine before being dried over magnesium sulfateand filtered. The solution was concentrated under reduced pressure. Theresidue was purified by flash column chromatography, using ethylacetate-iso-hexane (10:90 increasing to 25:75) as eluent, to afford thetitle compound (30 mg, 5%). MS [MH]⁺ 447.

Step 7

Compound 36

1-(2-Carbomethoxy)benzyl-3-[3-chloro-4-(N-methyl-N-2-pyridyl)aminomethyl]phenylpyrazole(28 mg, 0.06 mmol) was stirred in a solution of aqueous sodium hydroxide(1.0 M, 0.5 ml) and methanol (3 ml) at ambient temperature forapproximately 16 hours. The methanol was removed under reduced pressure,and the aqueous residue was washed using ethyl acetate. The aqueousphase was acidified using dilute hydrochloric acid (1.0 M) and theresulting solution was extracted into diethyl ether. The extracts weredried over magnesium sulfate, filtered and concentrated under reducedpressure to afford the title compound (22 mg, 81%) as a solid. MS [MH]⁺431 NMR d_(H) (d₆-DMSO) 3.1 (3H, s), 4.9 (2H, s), 5.8 (2H, s), 6.7 (2 H,m), 6.9 (2H, m), 7.1 (1H, d), 7.4 (1H, m), 7.6 (2H, m), 7.7 (1H, m), 7.9(2H, m), 8.0 (1H, m), 8.1 (1H, m).

Example 10

Using a method analogous to that described in Examples 8 and 9, thecompounds listed in Table 5 were prepared.

TABLE 5 ester MS Exam- pre- (MH) ple cursor* + NMR δ (d₆-DMSO) 17 Ethyl463 0.8 (3H, t), 1.3 (2H, m), 1.7 (2H, m), 2.8 (2H, t), 5.4 (2H, s), 5.7(2H, s), 6.7 (2H, m), 7-7.8 (12H, m). 25 Methyl 397 3.1 (3H, s), 4.8(2H, s), 5.8 (2H, s), 6.7 (4H, m), 7.3 (2H, d), 7.5 (3H, m), 7.8 (2H,d), 7.9 (1H, m), 8.0 (1H, d), 8.1 (1H, m). 19 Ethyl 549 0.8 (6H, m),1.1-1.6 (8H, m), 2.2 (1H, m), 5.3 (2H, s), 5.7 (2H, s), 6.4 (1H, m), 6.7(2H, m), 7.1 (3H, m), 7.4 (4H, m), 7.8 (5H, m), 9.7 (1H, s).

*Ethyl ester precursors followed the route of Example 8 whilst methylester precursors followed the route of Example 9.

Example 111-(2-carboxybenzyl)-4-(3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethyl)phenylpyrazole(Compound 44 in Table 1)

Step 1

(N-methyl-N-2-pyridyl)-2-methoxy-4-iodobenzamide

4-iodo-2-methoxybenzoic acid (2.5 g, 9 mmol) dissolved in 25 mldichloromethane and 2 drops dimethylformamide was treated with oxalylchloride (1.66 ml, 19 mmol) in five 0.33 ml portions over 15 minuteswaiting for the effervescence to subside between additions. The reactionmixture was evaporated to dryness and the residue dissolved indichloromethane (15 ml). This solution was added dropwise to a solutionof 2-methylaminopyridine (972 mg, 9 mmol) and triethylamine (2.51 ml, 18mmol) in dichloromethane (20 ml). The reaction was allowed 1 hour,washed with water twice and evaporated down to an oil. The crude oil waseluted down a 20 g Varian MegaBond Elut® column using 20-30% v/v ethylacetate in isohexane. The product containing fractions were grouped andevaporated to an oil which solidified on standing. The resulting solidwas dried under high vacuum (3.12 g): NMR δ (CDCl₃) 3.51 (3 H, s) 3.62(3 H, s) 7.04 (4 H, m) 7.26 (1H, d) 7.47 (1 H, t) 8.39 (1 H, d); MS[MH⁺] 369.1

Step 2

1-iodo-3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethylbenzene

Trichlorosilane (0.5 mL 4.95 mmol) disolved in 2 ml toluene was added to(N-methyl-N-2-pyridyl)-2-methoxy-4-iodobenzamide (300 mg, 0.815 mmol) in2 ml toluene under an argon atmosphere. The reaction was refluxed for 20hours, cooled, diluted with dichloromethane and gently treated withwater until effervescence subsided. The mixture was then basified withsolid KOH to pH 13, the phases separated and the aqueous extracted withdichloromethane twice. The combined organic extracts were evaporated toan oil (285 mg at 100% strength): NMR δ (CDCl₃) 3.1 (3 H, s) 3.83 (3 H,s) 4.67 (2 H, s) 6.44 (1 H, d) 6.53 (1 H, dd) 6.74 (1 H, d) 7.18 (2 H,m) 7.4 (1 H, m) 8.17 (1 H, dd); MS [MH⁺] 355.2

Step 3

1-pinacolboronate-3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethylbenzene

To an argon inerted flask was charged the1-iodo-3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethylbenzene (87 mg),0.246 mmol), PdCl₂(dppf) (6 mg, 0.0074 mmol) potassium acetate (72.4 mg,0.737 mmol), bis pinacolato diboron (69 mg, 0.272 mmol) and dimethylsulphoxide (4 ml). The reaction was heated to 80° C. and after 5 minutescooled to ambient. The reaction was quenched with water and extractedwith dichloromethane 3 times. The combined dichloromethane extracts werewashed with water and evaporated to an oil. The oil was eluted down a 10g Varian Mega Bond Elute column with 5-30% ethyl acetate in isohexane.The product containing fractions were combined and evaporated to an oil(58 mg): NMR δ (CDCl₃) 1.33 (12 H, s) 3.16 (3 H, s) 3.9 (3 H, s) 4.73 (2H, s) 6.43 (1 H, d) 6.51 (1 H, m) 7.05 (1 H, d) 7.33 (3 H, m) 8.16 (1 H,d); MS [MH⁺] 355.4

Step 4

1-(2-Carboethoxybenzyl)-4-iodopyrazole

To a solution of ethyl-(2-bromomethyl)benzoate (1.0 g, 4.12 mmol) indimethylformamide (10 ml) was added potassium carbonate (625 mg, 4.52mmol), potassium iodide (10 mg, 0.06 mmol) and 4-iodopyrazole (879 mg,4.53 mmol). The reaction was stirred at ambient for 15 minutes, then at60° C. for 2 hours. The reaction was cooled down to ambient, filtered,the residues washed with DMF and the combined filtrates evaporated downto an oil. The crude oil was eluted down a 20 g Varian Mega Bond Elut®column with 0-6% ethyl acetate in isohexane. The fractions containingthe product were combined and evaporated down to isolate the product asan oil (930 mg): NMR δ (CDCl₃) 1.4 (3 H, t) 4.39 (2 H, q) 5.75 (2 H, s)6.99 (1 H, d) 7.36 (1 H, t) 7.46 (1 H, t) 7.55 (2 H, s) 8.02 (1 H, d);MS [MH⁺] 357.1

Step 5

1-(2-carboethoxybenzyl)-4-(3-methoxy-4-methyl-N-2-pyridyl)aminomethyl)phenylpyrazole

To an argon inerted flask was charged1-pinacolboronate-3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethylbenzene(58 mg, 0.164 mmol), 1-(2-Carboethoxybenzyl)-4-iodopyrazole (58 mg,0.164 mmol), potassium carbonate (34 mg, 0.246 mmol), PdCl₂(dppf) (2.6mg, 0.0032 mmol) and dimethylformamide (4 ml). The reaction was stirredat 60° C. for 2.5 hours, cooled to ambient, quenched with water andextracted with dichloromethane 3 times. The combined extracts werewashed with water and evaporated to an oil. The crude oil was eluteddown a 10 g Varian Mega Bond Elut® column with 5-30% ethyl acetate inisohexane. The product containing fractions were combined and evaporateddown to isolate the product as an oil (57 mg): NMR δ (CDCl₃) 1.39 (3 H,t) 3.13 (3 H, s) 3.88 (3 H, s) 4.38 (2 H, q) 4.72 (2 H, s) 5.78 (2 H, s)6.47 (1 H, d) 6.52 (1 H, m) 6.99 (4 H, m) 7.4 (3 H, m) 7.72 (1 H, s) 7.8(1 H, s) 8.02 (1 H, d) 8.18 (1 H, d); MS [MH⁺] 457.2

Step 6

(Compound 44)

1-(2-carboethoxybenzyl)-4-(3-methoxy-4-(N-methyl-N-2-pyridyl)aminomethyl)phenylpyrazole(134 mg, 0.29 mmol) and 1M aq lithium hydroxide (0.59 ml, 0.59 mmol)were refluxed in ethanol (5 ml) for 2.5 hours. The reaction mixture wasevaporated to dryness and the residue partitioned betweendichloromethane and water. 0.96 N hydrochloric acid (0.61 ml, 0.59 mmol)was added to the mixture, the phases stirred and separated. The aqueousphase was extracted with dichloromethane and the combined organicextracts washed with water and then evaporated to a foam which wasbroken up to a solid (85 mg at 100% strength): NMR δ (CDCl₃) 3.12 (3 H,s) 3.83 (3 H, s) 4.75 (2 H, s) 5.51 (2 H, s) 6.58 (2 H, m) 6.85 (2 H, m)6.99 (2 H, m) 7.42 (3 H, m) 7.61 (1 H, s) 7.78 (1 H, s) 8.02 (1 H, d)8.29 (1 H, d); MS [MH⁺] 429.3

Example 12 Preparation of2-(2-carboxybenzyl)-5-[4-(2-quinolylmethoxy)phenyl]TETRAZOLE (Compound33 in Table 1)

Step 1

5-(4-hydroxyphenyl)tetrazole

A mixture of 4-cyanophenol (4.8 g, 40 mmol), sodium azide (7.8 g, 120mmol) and triethylamine hydrochloride (8.24 g, 60 mmol) in1-methyl-2-pyrrolidinone (40 ml) was stirred and heated in an oil bathat 140° C. for five hours. The cooled solution was acidified with 2Mhydrochloric acid (200 ml) and extracted with ethyl acetate (3×100 ml).The combined ethyl acetate extracts were washed with water (3×100 ml),dried over anhydrous magnesium sulphate, filtered and evaporated to afawn solid which was crystallised from 50% v/v ethyl acetate inisohexane to give the title compound (5.1 g.) NMR d (d₆-DMSO) 6.95(2H,d), 7.85 (2H,d), 10.13 (1H,br); MS[MH]⁺ 163

Step 2

2-(carboethoxybenzyl)-5-(4-hydroxyphenyl)tetrazole

A mixture of 5-(4-hydroxyphenyl)tetrazole (1.62 g, 10 mmol),2-carboethoxybenzylbromide (2.91 g, 12 mmol) and sodium hydrogencarbonate (1.7 g, 20 mmol) in N,N-dimethylformamide (10 ml) was stirredat ambient temperature for 16 hours. The mixture was then diluted withwater (40 ml) and extracted with ethyl acetate (3×20 ml). The ethylacetate extracts were washed with water (3×20 ml), dried over anhydrousmagnesium sulphate, filtered and evaporated to an oil.

This oil was purified by flash chromatography on a Varian 20 g silicamegabondelut column eluting with 10% to 40% v/v ethyl acetate inisohexane to give the title compound (2.2 g) as a white solid. NMR d(d₆-DMSO) 1.35 (3H,t), 4.3 (2H,q), 6.3 (2H,s), 6.98 (2H,d), 7.4 (1H,d),7.65 (1H,t), 7.7 (1H,t), 7.9 (2H,d), 8.02 (1H,d), 10.0 (1H,s); MS[MH]⁺325

Step 3

2-(2-carboethoxybenzyl)-5-[4(2-quinolylmethoxy)phenyl]tetrazole

A mixture of 2-(carboethoxybenzyl)-5-(4-hydroxyphenyl)tetrazole (182 mg,0.56 mmol), 2-chloromethylquinoline hydrochloride (107 mg, 0.5 mmol),potassium carbonate (276 mg, 2.0 mmol) and potassium iodide (20 mg) inN,N-dimethylformamide (3.0 ml) was stirred at ambient temperature for 24hours. The mixture was diluted with water (20 ml), and aqueous saturatedsodium carbonate solution (5.0 ml) was added. The mixture was stirredfor 15 minutes then the precipitate was filtered off, washed with waterand dried to give the title compound. (200 mg). NMR d (d₆-DMSO) 1.25(3H,t), 4.25 (2H,q), 5.44 (2H,s), 6.24 (2H,s), 7.22 (2H,d), 7.3 (1H,d),7.52 (1H,t), 7.6 (2H,m), 7.7(1H,d), 7.78 (1H,t), 7.98 (5H,m), 8.4(1H,d); MS[MH]⁺ 466

Step 4

Compound 33

A mixture of2-(2-carboethoxybenzyl)-5-[4-(2-quinolylmethoxyphenyl]tetrazole (150 mg,0.322 mmol) and 1M aqueous lithium hydroxide (1 ml, 1.0 mmol) in ethanol(5.0 ml) was stirred and heated at reflux temperature for 30 minutes.The mixture was cooled and acidified with concentrated hydrochloric acid(0.5 ml). The precipitate which formed on standing was collected byfiltration, washed with ethanol and dried to give the title compound(130 mg) as the hydrochloride salt. NMR d (d₆-DMSO) 5.35 (2H, br), 5.6(2H, s), 6.3 (2H, s), 7.2 (3H,m), 7.5 (1H,t), 7.6 (1H,t), 7.7(1H,t), 7.8(1H,d), 7.85 (1H,t), 8.02 (3H,d), 8.1 (1H,d), 8.15 (1H,d), 8.6 (1H,d);MS[MH]⁺ 438

Example 13 Biological Assays

(a) Ligand Binding Assay

The assay was based on a scintillation proximity assay in which thedisplacement of radiolabelled [³H] BRL 49653 (rosiglitazone) bindingfrom biotinylated human PPARγ-recombinant protein was measured. ThePPARγ ligand binding domain (LBD) of human PPARγ1 was expressed inE-Coli as a poly his and c-myc tagged fusion protein. Compounds of theinvention were incubated with [³H] BRL 49653, 30 nM (0.1 mCi),biotinylated human PPARg LBD protein (150 ng) and streptavidin SPAbeads, 025 mg/well. Compounds were able to displace radiolabel and sohave pharmacological potential as PPARγ agonists or antagonists.

(B) Cell Transactivation Assays

Assays were performed by transient transfection of Hepa1c1c7 cells inwhich compounds of the invention were tested for their ability toactivate human PPARα, δ and γ isoforms. Cells were co-transfected witheither PPARa, d and g expression vectors (containing the entire ORFsequence) and a reporter construct carrying a PPRE linked Lac Zconstruct. Cells were transfected using Superfect and cultured in T75flasks overnight, then plated into 96 well plates and left for 5 hoursbefore the addition of test compound. After a further 24 hours PPARactivation was quantitated indirectly as β-Galactosidase activity byhydrolysis of chlorophenol red-β-D-galactopyranoside (CPRG), measuredspectrophotometrically at 580 nm. Compounds of the invention were activein this assay. For example Compound 46 in Table 1 at a concentration of10 μM showed a γ transactivation of 64% and an α transactivation of 25%.

According to their activity in transactivation assays and by comparisonto the selective PPARγ agonist, BRL 49653; compounds of the inventionwere categorised as either having pharmacological properties consistentwith: selective PPARγ agonists, partial agonists or non-selective PPARα/γ agonists.

Adipocyte Differentiation Assay

3T3L1 preadipocytes were grown in DMEM containing 10% NBCS and 1 daypost-confluence cells were cultured in differentiation medium (DMEMcontaining 5% FCS, 1 μg/ml insulin, 0.25 μM dexamethasone and 0.5 mMIBMX) in the presence or absence of compounds. BRL 49653 was used as thepositive control and the medium replenished after 3 days. On day 7,cells were lysed and glycerophosphate dehydrogenase activity measuredspectrophotometrically at 340 nm. Under the conditions of the assay BRL49653 induces a dose related increase in glycerophosphate dehydrogenaseactivity. Compounds of the invention which were found to activate PPARγin the transactivation assay (vide supra) induced glycerophosphatedehydrogenase activity in 3T3L1 cells in a dose-related manner. Forexample, Compound 46 in Table 1 at a concentration of 10 μM showedactivity at 79% as compared to the control.

What is claimed is:
 1. A method for treatment of type 2 diabetes,treatment of insulin resistance syndrome (IRS), treatment ofdyslipidemia or reducing the risk of cardiovascular disease comprisingadministering to a patient in need thereof a therapeutically effectiveamount of a compound of formula (I)

or a pharmaceutically acceptable salt or ester thereof, optionally incombination with a pharmaceutically acceptable excipient, where Q, X, Yand Z are either —CR^(a)═, —CR^(b)═CR^(c)— or —N═; where R^(a), R^(b)and R^(c) are independently selected from hydrogen, halo or a bond, suchthat together with the nitrogen atom to which Y and Z are attached, theyform a five- or six-membered aromatic ring; R¹ and R³ are independentlyselected from C₁₋₃alkyl, halo, haloC₁₋₃alkyl, C₁₋₃alkoxy, orhaloC₁₋₃alkoxy; n and m are independently selected from 0, 1 or 2; A isan alkylene, alkenylene or alkynylene chain optionally interposed by aheteroatom; and R² is an optionally substituted aryl, optionallysubstituted heterocyclyl or optionally substituted cycloalkyl moiety. 2.The method as claimed in claim 1 wherein the group comprising —Y—X—Q—Z—and the nitrogen to which it is attached form a 5-membered aromaticring.
 3. The method as claimed in claim 1 or claim 2, wherein, in thecompound of formula I the carboxylic acid group is at the ortho positionon the benzyl ring.